Patent US1773116A successfully refreshed from Google Patents.
US3797487A
Expired / Lapsed
US
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Hypodermic syringe with clutch for aspiration
Assignee: Woelm Pharma GmbH and Co
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Filing: 1971-10-27
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Granted: 1974-03-19
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Expires: 1991-10-27
Abstract
Abstract A hypodermic syringe by which aspiration as well as injection can be effected, for example for the purpose of testing to see if the cannula has been inserted into a correct tissue of the patient. The syringe includes an operating lever for engaging a clutch acting between the piston rod or plunger of the syringe and a slide mounted co-axially on the piston rod and slidable thereon in a housing formed by part of the body of the syringe. The clutch can be released or engaged by the user while he is gripping the piston rod with the same hand, and thereby he can readily control the aspiration volume.
Inventors
- 👤 Guenther Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:19
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/178; A61M5/24; A61M5/31; A61M5/3148; A61M2005/2403; A61M2005/2407; A61M2005/2414; A61M2005/2485; A61M2005/2488; Y; Y10; Y10S; Y10S604/00; Y10S604/90
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
175 words
A hypodermic syringe having an aspiration device, the syringe including a housing with finger grip means attached thereto, a piston rod slidably positioned in said housing and extending therefrom, a hand grip attached to the extending end of the piston rod and means on one end of the said housing for attaching a hypodermic needle, and the aspiration device comprising a second housing connected to the other end of said syringe housing and slidably receiving the extending portion of said piston rod, a slide member within said second housing which is slidable coaxially with the piston, an operating lever connected to said slide member, said slide member responsive to movement of said lever, a spring for returning the slide member to an initial position after releasing the operating lever and a clutch provided between the slide member and the piston rod and operable by the slide member to engage the slide member with the piston rod, whereby the piston rod is moved in response to movement of the operating lever for the purpose of aspiration.
Claim 2
Dependent Claim
175 words
A hypodermic syringe having an aspiration device, the syringe including a housing with finger grip means attached thereto, a piston rod slidably positioned in said housing and extending therefrom, a hand grip attached to the extending end of the piston rod and means on one end of the said housing for attaching a hypodermic needle, and the aspiration device comprising a second housing connected to the other end of said syringe housing and slidably receiving the extending portion of said piston rod, a slide member within said second housing which is slidable coaxially with the piston, an operating lever connected to said slide member, said slide member responsive to movement of said lever, a spring for returning the slide member to an initial position after releasing the operating lever and a clutch provided between the slide member and the piston rod and operable by the slide member to engage the slide member with the piston rod, whereby the piston rod is moved in response to movement of the operating lever for the purpose of aspiration.
Claim 3
Dependent Claim
144 words
A syringe as claimed in claim 1 in which the slide member has a frusto-conical bore widening towards the end oF the piston rod to be gripped by the user, the clutch including a plurality of balls acting as clutch elements and positioned in an annular space between the frusto-conical bore of the slide and the piston rod, said balls being urged to grip the piston rod by wedging action of the frusto-conical bore pursuant to axial movement fo the slide in a direction to reduce the radial clearance between the bore and the piston rod, and a stop member which extends into the conical bore when the slide member has been moved to its initial position and by which the balls are held free from engagement between the piston rod and the frustor-conical bore, said stop member forming a support for said balls.
Claim 4
Dependent Claim
41 words
A syringe as claimed in claim 2 in which the slide member is movable in a housing, the housing being provided with diametrically-opposite slots extending axially of the housing and through which the operating lever is connected to the slide member.
Claim 5
Dependent Claim
21 words
A syringe as claimed in claim 3 further comprising resilient means for urging the balls into engagement with the stop member.
Claim 6
Dependent Claim
33 words
A syringe as claimed in claim 4, said resilient means comprising an axially compressible resilient ring provided in the housing around the piston rod and engageable between the balls and the slide member.
Claim 7
Dependent Claim
40 words
A syringe as claimed in claim 3 in which stub shafts are provided on the operating lever, the stub shafts extending in opposite directions to each other through the slots in the housing into blind holes in the slide member.
Claim 8
Dependent Claim
40 words
A syringe as claimed in claim 6 in which a fulcrum for the operating lever is provided by a plate defining a fixed abutment spaced from the axis of the stub shafts and against which the lever can be swivelled.
Claim 9
Dependent Claim
34 words
A syringe as claimed in claim 7 in which the plate defining the fixed abutment is positioned between the stub shafts and the end of the operating lever to be gripped by the user.
Claim 10
Dependent Claim
44 words
A syringe as claimed in claim 3 in which the operating lever comprises two arms in the form of a fork, the end of the arms remote from the end which is to be gripped by the user being engageable with a fixed abutment.
Claim 11
Dependent Claim
23 words
A syringe as claimed in claim 9 in which said fixed abutment is a flat surface provided on the outside of the housing.
Claim 12
Dependent Claim
25 words
A syringe as claimed in claim 3 in which the operating lever is formed in the shape of a substantially rectangular frame surrounding the housing.
Claim 13
Dependent Claim
82 words
A syringe as claimed in claim 3 in which the operating lever is pivotally mounted on the housing at the end thereof remote from the end which is to be gripped by the user, the slide member including pins projecting through the slots in the housing and being engageable with the lever in such a way that the clutch will be engaged when the lever is pulled towards the end of the piston rod that is to be gripped by the user.
Claim 14
Dependent Claim
34 words
A syringe as claimed in claim 2 in which movement of the slide member to its initial position by the return spring releases the clutch to disconnect the slide member from the piston rod.
Claim 15
Dependent Claim
35 words
A syringe as claimed in claim 13 in which the return spring for the slide member is a compression spring co-axially mounted on the piston rod and acting between the housing and the slide member.
Claim 16
Dependent Claim
20 words
A syringe as claimed in claim 2 including a pair of fixed stops between which the slide member is movable.
Claim 17
Dependent Claim
20 words
A syringe as claimed in claim 4, said resilient means comprising a second spring positioned co-axially within the slide-returning spring.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |